The Borussia Dortmund striker was expected to join German rivals Bayern Munich this summer but reports have suggested that his current employers are desperate not to sell him to the Bundesliga champions and would prefer him to join a foreign club.

That has put United at the front of the queue for a player valued at around £25m, but Barcelona could put in a bid of their own.

The Catalan giants have already signed Neymar but with uncertainty over the future of David Villa they could be in the market for another centre-forward.

And Intereconomia TV claim that Barca are ready to make a move for Lewandowski, perhaps using youngster Gerard Deulofeu in a part-exchange deal.

That could prompt United into making a formal bid of their own, with Dortmund likely to encourage interest in a player who starred in the Champions League this season.

And with Lewandowski's contract expiring in the summer of 2014, the Pole could well be on his way out of Jurgen Klopp's side ahead of next season.